[Vaska]

Need to scan for codes. Sometimes the error follows misfires.

[MakCamaro]

I will use HP Tuners to scan for codes and I will see what I get.

[MakCamaro]

So I connected HP Tuners and these are the codes I got:

0x543: C0800 - Device Power Circuit Malfunction (Pending)
0x543: U0140 - Lost Communication With Body Control Module (Pending, History)
0x543: U042B - Invalid Data Received from Chassis Control Module A (Pending, History)

Any idea if these are related to the Service Rear Axle issue?

[travislambert]

Originally Posted by MakCamaro

So I connected HP Tuners and these are the codes I got:

0x543: C0800 - Device Power Circuit Malfunction (Pending)
0x543: U0140 - Lost Communication With Body Control Module (Pending, History)
0x543: U042B - Invalid Data Received from Chassis Control Module A (Pending, History)

Any idea if these are related to the Service Rear Axle issue?

Yes, C0800 will cause a service rear axle to trigger. With this code present, the eLSD won't even attempt a self test. It immediately faults.

[MakCamaro]

Thanks travislambert. I did a quick search and it seems that the reason for this code is that the control module or sensor detects a system voltage of less than approximately 9 V or greater than 18 V for approximately 5 seconds. Any ideas what could be the cause for this?

[travislambert]

Originally Posted by MakCamaro

Thanks travislambert. I did a quick search and it seems that the reason for this code is that the control module or sensor detects a system voltage of less than approximately 9 V or greater than 18 V for approximately 5 seconds. Any ideas what could be the cause for this?

I've seen it trigger on Camaros that have been converted to race cars. These cars have a battery power disconnect switch. If this switch is turned off before the computers shut down gracefully, sometimes residual power in the capacitors etc. will cause the code to trigger.

I'm sure there are other causes, but that's the one I'm familiar with.

Do you have any aftermarket modules in the car?

[MakCamaro]

No there are no aftermarket modules on the car. As I described above it only happened once, so maybe it's a random thing. I drove the car several times after I saw this message and everything seems to be fine.

One thing that I forgot to mention is that I was away on a trip and the car was sitting in the garage for a month. Maybe this affected the battery charge, which could explain a temporary lower battery voltage. From what I've seen in other threads this "Service Rear Axle" message seems to be related to voltage fluctuations.

[travislambert]

Originally Posted by MakCamaro

No there are no aftermarket modules on the car. As I described above it only happened once, so maybe it's a random thing. I drove the car several times after I saw this message and everything seems to be fine.

One thing that I forgot to mention is that I was away on a trip and the car was sitting in the garage for a month. Maybe this affected the battery charge, which could explain a temporary lower battery voltage. From what I've seen in other threads this "Service Rear Axle" message seems to be related to voltage fluctuations.

Yeah, it's certainly related to voltage fluctuations via the C0800 that prevent the eLSD self-test from running. I'm confident with having this code there is absolutely nothing to worry about with the rear axle.

I know it's a real pain for the guys with race cars who like to disconnect their battery completely when the cars are stored. It's just strange to me because I disconnect my battery frequently to work on my car and have never had the problem. I assume because my car has all of its modules, the power consumption is enough to pull down the voltage completely within the grace period. On a race car that has been stripped, there aren't as many modules so my assumption is that they'd need much more time to fully discharge all of the capacitors. From the car's perspective, it looks like a low-voltage condition.

I have a feeling the C0800 has other criteria that aren't documented. It's hard to imagine your car hitting the published criteria, but I agree that it's related to the state of the battery in some way.

[MakCamaro]

Thanks again for all this info travislambert. I will keep an eye - mainly because I am OCD with the car - and will report back here if I see this happening again.

[Alain]

I had the same issue a few weeks back. It was preceded by a rough start up in the morning. The car sounded rough when it first started, it was running rough for a few seconds. I flipped the throttle as I was reversing out of the driveway and black-ish smoke came out of the exhaust.
Car ran perfectly fine the rest of the day, when I restarted it later that day it started fine and the code was gone

[juice3]

I had recurring issues with these codes. Fresh battery and no more issues. I have talked with Alex Doss several times. These cars are stupid finicky on voltage. Log voltage if you want or just put a new battery in an report back.

[MakCamaro]

Thanks, I might do that if I get these codes or the the Service Rear Axle message again. By the way, which batter do you suggest?

[clg82]

Don't mean to steal your thread Mak, but I think it's worth asking for those of us that don't drive our cars as much so they sit, what is everyone using as a battery tender so that we can keep our batteries fresh?

[814LT4]

Originally Posted by clg82

Don't mean to steal your thread Mak, but I think it's worth asking for those of us that don't drive our cars as much so they sit, what is everyone using as a battery tender so that we can keep our batteries fresh?

CTEK. I have the MXS 5.0, it works great as a charger and tender.